Specific to rear derailleurs (or rear mechs), which I think seems to be your question:
- to add tension to a rear derailleur cable, un-screw the barrel adjuster, like you want to loosen a screw. In this case, you would be turning the barrel adjuster counter clockwise.
(why add tension to the cable? because when you shift from small sprockets to big sprockets, it's not shifting or not shifting completely)
- to remove tension, turn the barrel to TIGHTEN (clockwise).
(why remove tension? you are getting poor shifting going from big sprockets to small sprockets, and you've added to much tension to the cable from step one.
- when you install the cable, the shifter should be in the position of the smallest sprocket, the barrel should be all the way "tightened" to the derailleur, and you should pull the cable as much as possible with some needle nose pliers.
or - just go read Sheldon Brown:
https://www.sheldonbrown.com/derailer-adjustment.html
- I'm going to go read about B-screw adjustment now. Ciao!
Originally Posted by
Learning here
When everyone so casually throws around sentences like "Turn the barrel clockwise..." what do they mean? Should I look at the shifter mech along the barrel, my face is at the center of the bike, looking at the handlegrips, and I need to see the barrel adjuster as a clock, and turn it clockwise?
Or do I have it backwards? Should I be seeing the barrel as a tiny clock as I face the center of the bike from off to one side???? Likewise minor brake adjustments.
Of course, for the barrel down on the rear derailler, there is the same question, but it is 90 degrees turned. What is the system? This is so basic, I feel foolish asking, and I know I can just experiment, but please tell me, thanks.